<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
 <head>
  <meta http-equiv="content-type" content="text/html; charset=UTF-8">
  <title>返回数组中指定的一列</title>

 </head>
 <body><div class="manualnavbar" style="text-align: center;">
 <div class="prev" style="text-align: left; float: left;"><a href="function.array-chunk.html">array_chunk</a></div>
 <div class="next" style="text-align: right; float: right;"><a href="function.array-combine.html">array_combine</a></div>
 <div class="up"><a href="ref.array.html">数组 函数</a></div>
 <div class="home"><a href="index.html">PHP Manual</a></div>
</div><hr /><div id="function.array-column" class="refentry">
 <div class="refnamediv">
  <h1 class="refname">array_column</h1>
  <p class="verinfo">(PHP 5 &gt;= 5.5.0)</p><p class="refpurpose"><span class="refname">array_column</span> &mdash; <span class="dc-title">返回数组中指定的一列</span></p>

 </div>
 <div class="refsect1 description" id="refsect1-function.array-column-description">
  <h3 class="title">说明</h3>
  <div class="methodsynopsis dc-description">
   <span class="type">array</span> <span class="methodname"><strong>array_column</strong></span>
    ( <span class="methodparam"><span class="type">array</span> <code class="parameter">$input</code></span>
   , <span class="methodparam"><span class="type"><a href="language.pseudo-types.html#language.types.mixed" class="type mixed">mixed</a></span> <code class="parameter">$column_key</code></span>
   [, <span class="methodparam"><span class="type"><a href="language.pseudo-types.html#language.types.mixed" class="type mixed">mixed</a></span> <code class="parameter">$index_key</code></span>
  ] )</div>

  <p class="para rdfs-comment">
   <span class="function"><strong>array_column()</strong></span>
   返回<em><code class="parameter">input</code></em>数组中键值为<em><code class="parameter">column_key</code></em>的列，
   如果指定了可选参数<em><code class="parameter">index_key</code></em>，那么<em><code class="parameter">input</code></em>数组中的这一列的值将作为返回数组中对应值的键。
  </p>
 </div>

 <div class="refsect1 parameters" id="refsect1-function.array-column-parameters">
  <h3 class="title">参数</h3>
  <p class="para">
   <dl>

    
     <dt>
<em><code class="parameter">input</code></em></dt>

     <dd>

      <p class="para">
       需要取出数组列的多维数组（或结果集）
      </p>
     </dd>

    
    
     <dt>
<em><code class="parameter">column_key</code></em></dt>

     <dd>

      <p class="para">
       需要返回值的列，它可以是索引数组的列索引，或者是关联数组的列的键。
       也可以是<strong><code>NULL</code></strong>，此时将返回整个数组（配合<em><code class="parameter">index_key</code></em>参数来重置数组键的时候，非常管用）
      </p>
     </dd>

    
    
     <dt>
<em><code class="parameter">index_key</code></em></dt>

     <dd>

      <p class="para">
       作为返回数组的索引/键的列，它可以是该列的整数索引，或者字符串键值。
      </p>
     </dd>

    
   </dl>

  </p>
 </div>

 <div class="refsect1 returnvalues" id="refsect1-function.array-column-returnvalues">
  <h3 class="title">返回值</h3>
  <p class="para">
   从多维数组中返回单列数组
  </p>
 </div>

 <div class="refsect1 examples" id="refsect1-function.array-column-examples">
  <h3 class="title">范例</h3>
  <p class="para">
   <div class="example" id="example-4834">
    <p><strong>Example #1 从结果集中取出first names列</strong></p>
    <div class="example-contents">
<div class="phpcode"><code><span style="color: #000000">
<span style="color: #0000BB">&lt;?php<br /></span><span style="color: #FF8000">//&nbsp;Array&nbsp;representing&nbsp;a&nbsp;possible&nbsp;record&nbsp;set&nbsp;returned&nbsp;from&nbsp;a&nbsp;database<br /></span><span style="color: #0000BB">$records&nbsp;</span><span style="color: #007700">=&nbsp;array(<br />&nbsp;&nbsp;&nbsp;&nbsp;array(<br />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</span><span style="color: #DD0000">'id'&nbsp;</span><span style="color: #007700">=&gt;&nbsp;</span><span style="color: #0000BB">2135</span><span style="color: #007700">,<br />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</span><span style="color: #DD0000">'first_name'&nbsp;</span><span style="color: #007700">=&gt;&nbsp;</span><span style="color: #DD0000">'John'</span><span style="color: #007700">,<br />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</span><span style="color: #DD0000">'last_name'&nbsp;</span><span style="color: #007700">=&gt;&nbsp;</span><span style="color: #DD0000">'Doe'</span><span style="color: #007700">,<br />&nbsp;&nbsp;&nbsp;&nbsp;),<br />&nbsp;&nbsp;&nbsp;&nbsp;array(<br />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</span><span style="color: #DD0000">'id'&nbsp;</span><span style="color: #007700">=&gt;&nbsp;</span><span style="color: #0000BB">3245</span><span style="color: #007700">,<br />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</span><span style="color: #DD0000">'first_name'&nbsp;</span><span style="color: #007700">=&gt;&nbsp;</span><span style="color: #DD0000">'Sally'</span><span style="color: #007700">,<br />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</span><span style="color: #DD0000">'last_name'&nbsp;</span><span style="color: #007700">=&gt;&nbsp;</span><span style="color: #DD0000">'Smith'</span><span style="color: #007700">,<br />&nbsp;&nbsp;&nbsp;&nbsp;),<br />&nbsp;&nbsp;&nbsp;&nbsp;array(<br />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</span><span style="color: #DD0000">'id'&nbsp;</span><span style="color: #007700">=&gt;&nbsp;</span><span style="color: #0000BB">5342</span><span style="color: #007700">,<br />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</span><span style="color: #DD0000">'first_name'&nbsp;</span><span style="color: #007700">=&gt;&nbsp;</span><span style="color: #DD0000">'Jane'</span><span style="color: #007700">,<br />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</span><span style="color: #DD0000">'last_name'&nbsp;</span><span style="color: #007700">=&gt;&nbsp;</span><span style="color: #DD0000">'Jones'</span><span style="color: #007700">,<br />&nbsp;&nbsp;&nbsp;&nbsp;),<br />&nbsp;&nbsp;&nbsp;&nbsp;array(<br />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</span><span style="color: #DD0000">'id'&nbsp;</span><span style="color: #007700">=&gt;&nbsp;</span><span style="color: #0000BB">5623</span><span style="color: #007700">,<br />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</span><span style="color: #DD0000">'first_name'&nbsp;</span><span style="color: #007700">=&gt;&nbsp;</span><span style="color: #DD0000">'Peter'</span><span style="color: #007700">,<br />&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</span><span style="color: #DD0000">'last_name'&nbsp;</span><span style="color: #007700">=&gt;&nbsp;</span><span style="color: #DD0000">'Doe'</span><span style="color: #007700">,<br />&nbsp;&nbsp;&nbsp;&nbsp;)<br />);<br />&nbsp;<br /></span><span style="color: #0000BB">$first_names&nbsp;</span><span style="color: #007700">=&nbsp;</span><span style="color: #0000BB">array_column</span><span style="color: #007700">(</span><span style="color: #0000BB">$records</span><span style="color: #007700">,&nbsp;</span><span style="color: #DD0000">'first_name'</span><span style="color: #007700">);<br /></span><span style="color: #0000BB">print_r</span><span style="color: #007700">(</span><span style="color: #0000BB">$first_names</span><span style="color: #007700">);<br /></span><span style="color: #0000BB">?&gt;</span>
</span>
</code></div>
    </div>

    <div class="example-contents"><p>以上例程会输出：</p></div>
    <div class="example-contents screen">
<div class="cdata"><pre>
Array
(
    [0] =&gt; John
    [1] =&gt; Sally
    [2] =&gt; Jane
    [3] =&gt; Peter
)
</pre></div>
    </div>
   </div>
  </p>
  <p class="para">
   <div class="example" id="example-4835">
    <p><strong>Example #2 
     从结果集中总取出last names列，用相应的id作为键值
    </strong></p>
    <div class="example-contents">
<div class="phpcode"><code><span style="color: #000000">
<span style="color: #0000BB">&lt;?php<br /></span><span style="color: #FF8000">//&nbsp;Using&nbsp;the&nbsp;$records&nbsp;array&nbsp;from&nbsp;Example&nbsp;#1<br /></span><span style="color: #0000BB">$last_names&nbsp;</span><span style="color: #007700">=&nbsp;</span><span style="color: #0000BB">array_column</span><span style="color: #007700">(</span><span style="color: #0000BB">$records</span><span style="color: #007700">,&nbsp;</span><span style="color: #DD0000">'last_name'</span><span style="color: #007700">,&nbsp;</span><span style="color: #DD0000">'id'</span><span style="color: #007700">);<br /></span><span style="color: #0000BB">print_r</span><span style="color: #007700">(</span><span style="color: #0000BB">$last_names</span><span style="color: #007700">);<br /></span><span style="color: #0000BB">?&gt;</span>
</span>
</code></div>
    </div>

    <div class="example-contents"><p>以上例程会输出：</p></div>
    <div class="example-contents screen">
<div class="cdata"><pre>
Array
(
    [2135] =&gt; Doe
    [3245] =&gt; Smith
    [5342] =&gt; Jones
    [5623] =&gt; Doe
)
</pre></div>
    </div>
   </div>
  </p>
 </div>

</div><hr /><div class="manualnavbar" style="text-align: center;">
 <div class="prev" style="text-align: left; float: left;"><a href="function.array-chunk.html">array_chunk</a></div>
 <div class="next" style="text-align: right; float: right;"><a href="function.array-combine.html">array_combine</a></div>
 <div class="up"><a href="ref.array.html">数组 函数</a></div>
 <div class="home"><a href="index.html">PHP Manual</a></div>
</div></body></html>
